photodetector

Abstract

A photodetector according to one embodiment of the present disclosure includes semiconductor substrate, a plurality of microlenses and a waveguide section provided between the semiconductor substrate and the plurality of microlenses. The waveguide section includes a multilayered structure arranged in a vertical direction and at least one layer of the multilayered structure is offset with respect to other layers of the multilayered structure in a horizontal direction. Each layer of the multilayered structure includes a color filter and at least one separation section provided between portions of the color filter. The at least one separation section includes an air gap provided therein.

Description

PHOTODETECTORCross Reference to Related Applications

[0001] This application claims the benefit of Japanese Priority Patent Application JP 2024-017374 filed on February 7, 2024, the entire contents of each which are incorporated herein by reference.

[0002] The present disclosure relates to a photodetector.

[0003] For example, PTL 1 discloses a solid-state imaging device that includes a plurality of waveguide wall parts arranged between color filters and surrounding the color filters. Each of the plurality of waveguide wall parts is provided at a position subjected to pupil correction. Thus, the solid-state imaging device achieves an improvement in pixel sensitivity and prevention of color mixture.

[0004] International Publication No. WO 2021 / 220610Summary

[0005] Incidentally, in a photodetector, an improvement in a spectral characteristic is desired.

[0006] It is desirable to provide a photodetector that makes it possible to improve a spectral characteristic.

[0007] A photodetector according to one embodiment of the present disclosure includes a semiconductor substrate, a plurality of microlenses, and an optical member. The semiconductor substrate has a first surface, and a second surface opposed to each other and includes a plurality of light-receiving sections arranged in an array in an in-plane direction. The plurality of microlenses is provided above the first surface of the semiconductor substrate. The optical member is provided between the first surface of the semiconductor substrate and the plurality of microlenses and includes a color filter and a separation section. The color filter separates incident light into a predetermined wavelength. The separation section separates the color filter and includes a plurality of layers having different refractive indices.

[0008] In the photodetector according to one embodiment of the present disclosure, in the optical member that is provided between the first surface of the semiconductor substrate and the plurality of microlenses and includes the color filter and the separation section, the separation section includes the plurality of layers having different refractive indices. The semiconductor substrate includes the plurality of light-receiving sections arranged in an array in the in-plane direction. The separation section separates the color filter. This suppresses scattering of oblique incident light by the separation section.

[0009] Fig. 1 is a schematic cross-sectional diagram illustrating an example of a configuration of a photodetector according to a first embodiment of the present disclosure.Fig. 2 is a schematic cross-sectional diagram illustrating another example of the configuration of the photodetector according to the first embodiment of the present disclosure.Fig. 3 is a block diagram illustrating an overall configuration of the photodetector illustrated in Fig. 1.Fig. 4 is an equivalent circuit diagram of a unit pixel illustrated in Fig. 1.Fig. 5 is a schematic plan diagram for describing a layout of separation sections illustrated in Fig. 2 at respective positions in a pixel section.Fig. 6A is a diagram describing the layout of the separation section at position A illustrated in Fig. 5.Fig. 6B is a diagram describing the layout of the separation section at position B illustrated in Fig. 5.Fig. 6C is a diagram for describing the layout of the separation section at position C illustrated in Fig. 5.Fig. 6D is a diagram for describing the layout of the separation section at position D illustrated in Fig. 5.Fig. 6E is a diagram for describing the layout of the separation section at position E illustrated in Fig. 5.Fig. 7 is a schematic cross-sectional diagram illustrating another example of the configuration of the photodetector according to the first embodiment of the present disclosure.Fig. 8A is a schematic cross-sectional diagram for describing a method of manufacturing the photodetector illustrated in Fig. 1.Fig. 8B is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 8A.Fig. 8C is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 8B.Fig. 8D is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 8C.Fig. 8E is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 8D.Fig. 8F is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 8E.Fig. 9 is a schematic cross-sectional diagram illustrating an example of a configuration of a photodetector according to Modification Example 1 of the present disclosure.Fig. 10 is a schematic cross-sectional diagram illustrating another example of the configuration of the photodetector according to Modification Example 1 of the present disclosure.Fig. 11A is a schematic cross-sectional diagram for describing a method of manufacturing the photodetector illustrated in Fig. 10.Fig. 11B is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 11A.Fig. 11C is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 11B.Fig. 11D is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 11C.Fig. 11E is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 11D.Fig. 11F is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 11E.Fig. 11G is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 11F.Fig. 11H is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 11G.Fig. 12 is a schematic cross-sectional diagram illustrating an example of a configuration of a photodetector according to Modification Example 2 of the present disclosure.Fig. 13 is a schematic cross-sectional diagram illustrating another example of the configuration of the photodetector according to Modification Example 2 of the present disclosure.Fig. 14 is a schematic cross-sectional diagram illustrating an example of a configuration of a photodetector according to Modification Example 3 of the present disclosure.Fig. 15 is a schematic cross-sectional diagram illustrating an example of a configuration of a photodetector according to Modification Example 4 of the present disclosure.Fig. 16 is a schematic cross-sectional diagram illustrating an example of a configuration of a photodetector according to Modification Example 5 of the present disclosure.Fig. 17 is a schematic cross-sectional diagram illustrating another example of the configuration of the photodetector according to Modification Example 5 of the present disclosure.Fig. 18 is a schematic cross-sectional diagram illustrating another example of the configuration of the photodetector according to Modification Example 5 of the present disclosure.Fig. 19 is a schematic cross-sectional diagram illustrating an example of a configuration of a photodetector according to Modification Example 6 of the present disclosure.Fig. 20 is a schematic cross-sectional diagram illustrating an example of a configuration of a photodetector according to Modification Example 7 of the present disclosure.Fig. 21 is a schematic cross-sectional diagram illustrating an example of the configuration of the photodetector according to Modification Example 7 of the present disclosure.Fig. 22 is a schematic cross-sectional diagram illustrating an example of a configuration of a photodetector according to a second embodiment of the present disclosure.Fig. 23A is a schematic cross-sectional diagram for describing a method of manufacturing the photodetector illustrated in Fig. 22.Fig. 23B is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 23A.Fig. 23C is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 23B.Fig. 23D is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 23C.Fig. 23E is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 23D.Fig. 23F is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 23E.Fig. 23G is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 23F.Fig. 23H is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 23G.Fig. 23I is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 23H.Fig. 23J is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 23I.Fig. 23K is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 23J.Fig. 23L is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 23K.Fig. 23M is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 23L.Fig. 24A is a schematic cross-sectional diagram for describing a method of manufacturing the photodetector illustrated in Fig. 22.Fig. 24B is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 24A.Fig. 24C is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 24B.Fig. 24D is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 24C.Fig. 24E is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 24D.Fig. 24F is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 24E.Fig. 24G is a schematic cross-sectional diagram illustrating a process subsequent to Fig. 24F.Fig. 25 is a block diagram illustrating a configuration example of an electronic apparatus including the photodetector illustrated in Fig. 1 or the like.Fig. 26A is a schematic diagram illustrating an example of an overall configuration of a photodetection system including the photodetector illustrated in Fig. 1 or the like.Fig. 26B is a diagram illustrating an example of a circuit configuration of the photodetection system illustrated in Fig. 26A.Fig. 27 is a view depicting an example of a schematic configuration of an endoscopic surgery system.Fig. 28 is a block diagram depicting an example of a functional configuration of a camera head and a camera control unit (CCU).Fig. 29 is a block diagram depicting an example of a schematic configuration of a vehicle control system.Fig. 30 is a diagram illustrating examples of installation positions of an outside-vehicle information detecting section and an imaging section.

[0010] Some embodiments of the present disclosure are described below in detail with reference to the drawings. The following description is a specific example of the present disclosure, and the present disclosure is not limited to the following embodiments. In addition, the present disclosure is not limited to arrangements, dimensions, dimension ratios, etc. of respective components illustrated in each drawing. It is to be noted that the description is given in the following order. 1. First Embodiment (An example of a photodetector) 2. Modification Examples 2-1. Modification Example 1 (Another example of a configuration of the photodetector) 2-2. Modification Example 2 (Another example of the configuration of the photodetector) 2-3. Modification Example 3 (Another example of the configuration of the photodetector) 2-4. Modification Example 4 (Another example of the configuration of the photodetector) 2-5. Modification Example 5 (Another example of the configuration of the photodetector) 2-6. Modification Example 6 (Another example of the configuration of the photodetector) 2-7. Modification Example 7 (Another example of the configuration of the photodetector) 3. Second Embodiment (An example of a photodetector) 4. Application Examples 5. Practical Application Examples <1. First Embodiment>

[0011] Fig. 1 and Fig. 2 each schematically illustrate an example of a cross-sectional configuration of a photodetector (a photodetector 1) according to a first embodiment of the present disclosure. Fig. 3 illustrates an example of an overall configuration of the photodetector 1 illustrated in Fig. 1 and Fig. 2. The photodetector 1 is, for example, a (Complementary Metal Oxide Semiconductor (CMOS) image sensor or the like included in an electronic apparatus such as a digital still camera or a video camera, and includes, as an imaging area, a pixel section (a pixel section 100A) including a plurality of pixels two-dimensionally arranged in a matrix. The photodetector 1 is, for example, what is called a back-illuminated photodetector in the CMOS image sensor or the like.

[0012] The photodetector 1 has a first surface 11S1 and a second surface 11S2 opposed to each other and includes a waveguide section 22 and a lens layer 23 in this order on the first surface 11S1 of a semiconductor substrate 11. The semiconductor substrate 11 includes a plurality of photoelectric conversion sections 12 arranged in an array in an in-plane direction of an XY plane. The waveguide section 22 includes a plurality of layers (for example, two layers, that is, a first layer 22A and a second layer 22B, or three layers, that is, the first layer 22A, the second layer 22B, and a third layer 22C), and the plurality of layers each include a corresponding one of color filters 221, 223, and 225, and a corresponding one of separation sections 222, 224, and 226 that respectively separate the color filters 221, 223, and 225. The separation sections 222, 224, and 226 are configured to have different refractive indices.

[0013] Here, semiconductor substrate 11 corresponds to a specific example of a "semiconductor substrate" in an embodiment of the present disclosure. The plurality of photoelectric conversion sections 12 corresponds to a specific example of a "plurality of light-receiving sections" in an embodiment of the present disclosure. The waveguide section 22 corresponds to a specific example of an "optical member" in an embodiment of the present disclosure. The lens layer 23 corresponds to a specific example of a "plurality of microlenses" in an embodiment of the present disclosure. The color filters 221, 223, and 225 each correspond to a specific example of a "color filter" in an embodiment of the present disclosure. The separation sections 222, 224, and 226 each correspond to a specific example of a "separation section" in an embodiment of the present disclosure.Schematic Configuration of Photodetector

[0014] The photodetector 1 takes in incident light (image light) from a subject through an optical lens system (for example, a lens group 1001; see Fig. 25), and converts a light amount of the incident light formed as an image on an imaging plane into electric signals in units of pixels to output the electric signals as pixel signals. The photodetector 1 includes the pixel section 100A as the imaging area on the semiconductor substrate 11. In addition, the photodetector 1 includes, for example, a vertical drive circuit 111, a column signal processing circuit 112, a horizontal drive circuit 113, an output circuit 114, a control circuit 115, and an input / output terminal 116 in a peripheral region of the pixel section 100A.

[0015] The pixel section 100A includes, for example, the plurality of unit pixels P two-dimensionally arranged in a matrix. The plurality of unit pixels P photoelectrically converts a subject image formed by an imaging lens in a photodiode PD to generate a signal for image generation.

[0016] For example, the unit pixels P are wired to a pixel drive line Lread (specifically, a row selection line and a reset control line) for each pixel row and are wired to a vertical signal line Lsig for each pixel column. The pixel drive line Lread transmits a drive signal for signal reading from a pixel. The pixel drive line Lread has one end coupled to an output end corresponding to each row of the vertical drive circuit 111.

[0017] The vertical drive circuit 111 is a pixel driving section that includes a shift register, an address decoder, and the like and drives the unit pixels P in the pixel section 100A in row units, for example. A signal outputted from each of the unit pixels P in a pixel row selected and scanned by the vertical drive circuit 111 is supplied to the column signal processing circuit 112 through a corresponding one of the vertical signal lines Lsig. The column signal processing circuit 112 includes an amplifier, a horizontal selection switch, and the like provided for each of the vertical signal lines Lsig.

[0018] The horizontal drive circuit 113 includes a shift register, an address decoder, and the like, and drives respective horizontal selection switches of the column signal processing circuits 112 in order while scanning the horizontal selection switches. Through such selective scanning performed by the horizontal drive circuit 113, the signals of respective pixels transmitted through respective vertical signal lines Lsig are outputted in order to a horizontal signal line 121, and the signals are transmitted outside of the semiconductor substrate 11 through the horizontal signal line 121.

[0019] The output circuit 114 performs signal processing on the signals supplied in order from the respective column signal processing circuits 112 through the horizontal signal line 121, and outputs the processed signals. The output circuit 114 performs, for example, only buffering in some cases, and performs black level adjustment, column variation correction, various types of digital signal processing, and the like in other cases.

[0020] A circuit portion including the vertical drive circuit 111, the column signal processing circuit 112, the horizontal drive circuit 113, the horizontal signal line 121, and the output circuit 114 may be formed directly on the semiconductor substrate 11 or may be provided on an external control integrated circuit (IC). Alternatively, the circuit portion may be formed on another substrate coupled by a cable or the like.

[0021] The control circuit 115 receives a clock signal provided from outside of the semiconductor substrate 11, or data or the like that provides an instruction as to an operation mode, and also outputs data such as internal information about the photodetector 1. The control circuit 115 further includes a timing generator that generates various timing signals, and controls driving of peripheral circuits such as the vertical drive circuit 111, the column signal processing circuit 112, and the horizontal drive circuit 113, based on t the various timing signals generated by the timing generator.

[0022] The input / output terminal 116 exchanges signals with the outside.Circuit Configuration of Unit Pixel

[0023] Fig. 4 illustrates an example of a readout circuit of the unit pixel P of the photodetector 1 illustrated in Fig. 3. For example, as illustrated in Fig. 4, the unit pixel P includes one photoelectric conversion section 12, a transfer transistor TR, a floating diffusion (FD), a reset transistor RST, an amplification transistor AMP, and a selection transistor SEL.

[0024] The photoelectric conversion section 12 includes a photodiode (PD). The photoelectric conversion section 12 has an anode coupled to a ground voltage line, and a cathode coupled to a source of the transfer transistor TR.

[0025] The transfer transistor TR is coupled between the photoelectric conversion section 12 and the floating diffusion FD. A drive signal TRsig is applied to a gate electrode of the transfer transistor TR. In a case where this drive signal TRsig is turned to an active state, a transfer gate of the transfer transistor TR is turned to an electrically conductive state, and a signal electric charge accumulated in the photoelectric conversion section 12 is transferred to the floating diffusion FD through the transfer transistor TR.

[0026] The floating diffusion FD is coupled between the transfer transistor TR and the amplification transistor AMP. The floating diffusion FD converts the signal electric charge transferred by the transfer transistor TR into a voltage signal through electric charge-voltage conversion, and outputs the voltage signal to the amplification transistor AMP.

[0027] The reset transistor RST is coupled between the floating diffusion FD and a power supply section. A drive signal RSTsig is applied to a gate electrode of the reset transistor RST. In a case where the drive signal RSTsig is turned to the active state, a reset gate of the reset transistor RST is turned to the electrically conductive state, and a potential of the floating diffusion FD is reset to a level of the power supply section.

[0028] The amplification transistor AMP has a gate electrode coupled to the floating diffusion FD, and a drain electrode coupled to the power supply section and serves as an input section of a readout circuit for a voltage signal held by the floating diffusion FD, that is, what is called a source follower circuit. In other words, the amplification transistor AMP has a source electrode coupled to the vertical signal line Lsig through the selection transistor SEL, thereby configuring a source follower circuit with a constant current source coupled to one end of the vertical signal line Lsig.

[0029] The selection transistor SEL is coupled between the source electrode of the amplification transistor AMP and the vertical signal line Lsig. A drive signal SELsig is applied to a gate electrode of the selection transistor SEL. In a case where the drive signal SELsig is turned to the active state, the selection transistor SEL is turned to the electrically conductive state to turn the unit pixel P to a selected state. Accordingly, a readout signal (a pixel signal) outputted from the amplification transistor AMP is outputted to the vertical signal line Lsig through the selection transistor SEL.Configuration of Unit Pixel

[0030] The photodetector 1 is, for example, a back-illuminated photodetector as described above, and the plurality of unit pixels P two-dimensionally arranged in a matrix in the pixel section 100A each has, for example, a configuration in which the light-receiving section 10, a light-condensing section 20, and a multilayer wiring layer 30 are stacked. The light-condensing section 20 is provided on light incident side S1 of the light-receiving section 10. The multilayer wiring layer 30 is provided on a side opposite to the light incident side S1 of the light-receiving section 10.

[0031] The light-receiving section 10 includes the semiconductor substrate 11 and the plurality of photoelectric conversion sections 12. The semiconductor substrate 11 has the first surface 11S1 and the second surface 11S2 opposed to each other. The plurality of photoelectric conversion sections 12 is provided to be embedded in the semiconductor substrate 11. The semiconductor substrate 11 includes, for example, a silicon substrate. Each of the photoelectric conversion sections 12 is, for example, a Positive Intrinsic Negative (PIN) type photodiode (PD), and includes a pn junction in a predetermined region of the semiconductor substrate 11. The photoelectric conversion sections 12 are each provided to be embedded for each of the unit pixels P.

[0032] The light-receiving section 10 further includes a pixel separation section 13.

[0033] The pixel separation section 13 is provided between adjacent unit pixels P. In other words, the pixel separation section 13 is provided around the unit pixels P, and is provided, for example, in a lattice form in the pixel section 100A. The pixel separation section 13 is provided to electrically and optically separate adjacent unit pixels P from each other. The pixel separation section 13 extends, for example, from the side of the first surface 11S1 toward side of the second surface 11S2 of the semiconductor substrate 11. It is possible to form the pixel separation section 13, for example, by diffusing a p-type impurity.

[0034] Although not illustrated, the first surface 11S1 of the semiconductor substrate 11 may be provided also with a fixed electric charge film. The fixed electric charge film also serves to prevent reflection at the first surface 11S1 of the semiconductor substrate 11. The fixed electric charge film may be a film having a negative fixed electric charge. Examples of a material included in the fixed electric charge film include a semiconductor material having a wider band gap than a band gap of the semiconductor substrate 11 and an electrically conductive material having a wider band gap than the band gap of the semiconductor substrate 11. Specific examples of the semiconductor material and the electrically conductive material include hafnium oxide (HfOx), aluminum oxide (AlOx), zirconium oxide (ZrOx), tantalum oxide (TaOx), titanium oxide (TiOx), lanthanum oxide (LaOx), praseodymium oxide (PrOx), cerium oxide (CeOx), neodymium oxide (NdOx), promethium oxide (PmOx), samarium oxide (SmOx), europium oxide (EuOx), gadolinium oxide (GdOx), terbium oxide (TbOx), dysprosium oxide (DyOx), holmium oxide (HoOx), thulium oxide (TmOx), ytterbium oxide (YbOx), lutetium oxide (LuOx), yttrium oxide (YOx), hafnium nitride (HfNx), aluminum nitride (AlNx), hafnium oxynitride (HfOxNy), and aluminum oxynitride (AlOxNy). The fixed electric charge film may be a single-layer film, or maybe a stacked film including different materials.

[0035] The light-condensing section 20 is provided on the light incident side S1 of the light-receiving section 10, and includes, for example, a protection layer 21, the waveguide section 22, and the lens layer 23 that are stacked in this order. The waveguide section 22 has a multilayer structure in which a plurality of layers is stacked. In one example, as illustrated in Fig. 1, the waveguide section 22 has a two-layer structure in which the first layer 22A and the second layer 22B are stacked in order from the side of the first surface 11S1 of the semiconductor substrate 11. In another example, as illustrated in Fig. 2, the waveguide section 22 has a three-layer structure in which the first layer 22A, the second layer 22B, and the third layer 22C are stacked in order from the side of the first surface 11S1 of the semiconductor substrate 11.

[0036] The protection layer 21 is provided to reduce deterioration in a dark time characteristic. The protection layer 21 is provided on the first surface 11S1 of the semiconductor substrate 11. In addition, a refractive index and a film thickness of a material of the protection layer 21 are appropriately set, which allows the protection layer 21 to suppress reflection of light caused by a refractive index difference between the semiconductor substrate 11 and, for example, the color filter 221. As a material included in the protection layer 21, a material having a lower refractive index than a refractive index of the fixed electric charge film described above is preferable. Examples of the material included in the protection layer 21 include silicon oxide (SiOx), silicon nitride (SiNx), and silicon oxynitride (SiOxNy).

[0037] The waveguide section 22 has a multilayer structure as described above. Each of the layers included in the waveguide section 22 includes a color filter and a separation section. The color filter separates incident light into a predetermined wavelength. The separation section separates the color filter for each unit pixel P, for example. Specifically, for example, in the photodetector 1 illustrated in Fig. 1, the waveguide section 22 has a two-layer structure in which the first layer 22A and the second layer 22B are stacked in order from the side of the first surface 11S1 of the semiconductor substrate 11. The first layer 22A includes the color filter 221 and the separation section 222 that separates the color filter 221 for each unit pixel P. The second layer 22B includes the color filter 223 and the separation section 224 that separates the color filter 223 for each unit pixel P. In the photodetector 1 illustrated in Fig. 2, the waveguide section 22 has a three-layer structure in which the first layer 22A, the second layer 22B, and the third layer 22C are stacked in order from the side of the first surface 11S1 of the semiconductor substrate 11. The third layer 22C includes the color filter 225 and the separation section 226 that separates the color filter 223 for each unit pixel P.

[0038] The color filters 221, 223, and 225 are each provided to separate the incident light into the predetermined wavelength as described above. In other words, the color filters 221, 223, and 225 each allow light having a predetermined wavelength to selectively pass therethrough and respectively include a green filter that allows green light (G) to selectively pass therethrough, a red filter that allows red light (R) to selectively pass therethrough, and a blue filter that allows blue light (B) to selectively pass therethrough. In addition, the color filters 221, 223, and 225 may include filters that allow cyan, magenta, and yellow to selectively pass therethrough. In the unit pixels P provided with filters of respective colors, for example, light of a corresponding color is detected in each of the photoelectric conversion sections 12. It is possible to form the color filters 221, 223, and 225 using, for example, a pigment or a dye. It is to be noted that it is possible to regard a layer including a transparent material as a color filter in a black-and-white pixel.

[0039] The separation sections 222, 224, and 226 respectively separate the color filters 221, 223, and 225 in the layers 22A, 22B, and 22C for each unit pixel P as described above. In other words, the separation sections 222, 224, and 226 are provided between the adjacent unit pixels P provided with color filters of different colors as color filters. The separation sections 222, 224, and 226 are each provided to prevent leakage of obliquely incident light into adjacently arranged unit pixels P. The separation sections 222, 224, and 226 are provided between the adjacent unit pixels P respectively in the layers 22A, 22B, and 22C, and are each provided in a lattice form in the pixel section 100A.

[0040] In the present embodiment, the separation sections 222, 224, and 226 of the respective layers are each provided at a position subjected to pupil correction depending on an incident angle of incident light L. In other words, the separation sections 222, 224, and 226 of the respective layers are each provided at a position shifted from a boundary between the adjacent unit pixels P partitioned by the pixel separation section 13 toward an optical center of the pixel section 100A, depending on a position in the pixel section 100A. An amount of the shift is larger in upper layers of the waveguide section 22.

[0041] Fig. 5 is a schematic plan diagram for describing a layout of the separation sections 222, 224, and 226 at the respective positions in pixel section 100A. In the unit pixel P provided at position A that is the optical center of the pixel section 100A, as illustrated in Fig. 6A, the separation sections 222, 224, and 226 are provided at substantially the same positions facing each other in a plan view. In contrast, in the unit pixel P provided at position B in an upper left corner of the pixel section 100A with respect to position A that is the optical center, as illustrated in Fig. 6B, the separation sections 222, 224, and 226 are so provided that the amount of the shift from an outer frame of the unit pixel P diagonally downward to the right, that is, toward the optical center is larger in upper layers of the waveguide section 22. In the unit pixel P provided at position C in an upper right l corner of the pixel section 100A with respect to position A that is the optical center, as illustrated in Fig. 6C, the separation sections 222, 224, and 226 are provided so that the amount of the shift from the outer frame of the unit pixel P diagonally downward to the left, that is, toward the optical center is larger in upper layers of the waveguide section 22. In the unit pixel P provided at position D in a lower left corner of the pixel section 100A with respect to position A that is the optical center, as illustrated in Fig. 6D, the separation sections 222, 224, and 226 are provided so that the amount of the shift from the outer frame of the unit pixel P diagonally upward to the right, that is, toward the optical center is larger in upper layers of the waveguide section 22. In the unit pixel P provided at position E in a lower right corner of the pixel section 100A with respect to position A that is the optical center, as illustrated in Fig. 6E, the separation sections 222, 224, and 226 are provided so that the amount of the shift from the outer frame of the unit pixel P diagonally upward to the left, that is, toward the optical center is larger in upper layers of the waveguide section 22.

[0042] In the present embodiment, the separation sections 222, 224, and 226 of the respective layers of the waveguide section 22 are formed using materials having different refractive indices. For example, the separation section 226 provided in an uppermost layer of the waveguide section 22in the photodetector 1 illustrated in Fig. 2 is formed using a material having a lower refractive index than refractive indices of the separation sections 222 and 224. In this case, the separation sections 222 and 224 may be formed using materials that are the same as each other or may be formed using materials different from each other so that the refractive index is lower in order of the separation sections 222, 224, and 226. Alternatively, the separation section 222 provided in a lowermost layer in the photodetector 1 illustrated in Fig. 2 may be formed using a material having a lower refractive index than the refractive indices of the separation sections 224 and 226. In this case, the separation sections 224 and 226 may be formed using materials that are the same as each other or may be formed using materials different from each other so that the refractive index is lower in order of the separation sections 226, 224, and 222. Accordingly, the separation section formed using a material having a lower refractive index is not particularly limited. A separation section of a layer in which light is desired to be narrowed is formed using a material having a lower refractive index to cause a refractive index difference between the separation section and a color filter adjacent to the separation section, which makes it possible to prevent leakage to the adjacently arranged unit pixels P.

[0043] It is possible to form the separation sections 222, 224, and 226 using, for example, silicon oxide (SiOx). In particular, silicon oxide (SiOx) having a refractive index n of 1.0 or less is used as a low refractive index material. Further, it is possible to form the separation section 222 in the lowermost layer or the separation section 224 in a second layer from the bottom using a metal material having a higher extinction coefficient than an extinction coefficient of the separation section 226 in the uppermost layer.

[0044] It is to be noted that the waveguide section 22 having a two-layer structure, or a three-layer structure has been described as an example with reference to Fig. 1 and Fig. 2; however, the number of layers included in the waveguide section 22 is not limited thereto. For example, as illustrated in Fig. 7, the waveguide section 22 may include N layers. In this case also, the separation sections 222, 224, ..., 22n of respective layers are each provided at a position subjected to pupil correction depending on the incident angle of the incident light L, and the separation section of at least one layer is formed using a material having a lower refractive index than refractive indices of other separation sections. This makes it possible to prevent leakage to the adjacently arranged unit pixels P.

[0045] The lens layer 23 is provided so as to cover the entire surface of the pixel section 100A, and has a front surface provided with a plurality of microlenses 23L. Each of the microlenses 23L is provided to collect into the first surface 11S1 serving as a light-receiving surface, light entering from above, and for example, is provided for each unit pixel P as illustrated in Fig. 1. The lens layer 23 including the microlenses 23L is formed using, for example, a high refractive index material. Specifically, the lens layer 23 is formed using, for example, an inorganic material such as silicon oxide (SiOx) or silicon nitride (SiNx). In addition, the lens layer 23 may be formed using an organic material having a high refractive index such as an episulfide-based resin, a thietane compound, or a resin thereof. The microlenses 23L are not particularly limited in shape, and it is possible to employ various types of lens shapes such as a half-sphere shape or a half-tubular shape.

[0046] The multilayer wiring layer 30 is provided on a side opposite to the light incident side S1 of the light-receiving section 10, specifically on the side of the second surface 11S2 of the semiconductor substrate 11. For example, the multilayer wiring layer 30 has a configuration in which a plurality of wiring layers 31, 32, and 33 is stacked with an interlayer insulating layer 34 interposed therebetween. In addition to the readout circuit described above, the vertical drive circuit 111, the column signal processing circuit 112, the horizontal drive circuit 113, the output circuit 114, the control circuit 115, the input / output terminal 116, and the like are provided on the multilayer wiring layer 30, for example.

[0047] The wiring layers 31, 32, and 33 are formed using, for example, aluminum (Al), copper (Cu), or tungsten (W). In addition, the wiring layers 31, 32, and 33 may be formed using polysilicon (Poly-Si).

[0048] For example, the interlayer insulating layer 34 includes a single-layer film including one of silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), or the like, or includes a stacked film including two or more thereof.Method of Manufacturing Waveguide Section

[0049] It is possible to form the waveguide section 22 of the photodetector 1 as follows, for example.

[0050] First, as illustrated in Fig. 8A, the separation section 222 is formed on the protection layer 21 by photolithography and an etching technique. In this case, although not illustrated, a metal film having a light-blocking property may be provided between the protection layer 21 and the separation section 222. Alternatively, a passivation film may be formed so as to cover an upper surface and a side surface of the separation section 222. Thereafter, as illustrated in Fig. 8B, the color filter 221 is formed so as to fill a gap between the separation sections 222. Thus, the first layer 22A is formed.

[0051] Thereafter, as with the first layer 22A, the second layer 22B and the third layer 22C are formed. Specifically, as illustrated in Fig. 8C, the separation section 224 is formed on the first layer 22A by photolithography and an etching technique. Thereafter, as illustrated in Fig. 8D, the color filter 223 is formed so as to fill a gap between the separation sections 224. Thus, the second layer 22B is formed. Thereafter, as illustrated in Fig. 8E, the separation section 226 is formed on the second layer 22B by photolithography and an etching technique. Thereafter, as illustrated in Fig. 8F, the color filter 225 is formed so as to fill a gap between the separation sections 226. Thus, the third layer 22C is formed.

[0052] Thereafter, the lens layer 23 including the plurality of microlenses 23L is bonded onto the third layer 22C. Thus, for example, the photodetector 1 illustrated in Fig. 2 is completed.

[0053] It is to be noted that in a case where it is difficult to form the separation section 224 (or 225) of an upper layer due to a height difference caused between the color filter 221 (or the color filter 223 or 225) and the separation section 222 (or the separation section 224 or 226) or roughness of the color filter 221 (or the color filter 223 or 225), or in a case where an etching stopper film is necessary when processing the separation section 224 (or 226) of the upper layer, a coating layer (for example, a coating layer 251 to be described later) may be provided.Workings and Effects

[0054] In the photodetector 1 according to the present embodiment, the waveguide section 22 including a plurality of layers is provided between the first surface 11S1 of the semiconductor substrate 11 and the lens layer 23. The semiconductor substrate 11 includes the plurality of photoelectric conversion sections 12 arranged in an array in the in-plane direction of the XY plane. The lens layer 23 includes the plurality of microlenses 23L that is each provided for each unit pixel P, for example. The respective layers (for example, the first layer 22A and the second layer 22B) included in the waveguide section 22 each includes a corresponding one of the color filters 221 and 223 and a corresponding one of the separation sections 222 and 224 that respectively separate the color filters 221 and 223, and the separation sections 222 and 224 are formed using materials having different refractive indices. This suppresses scattering of the obliquely incident light L by the separation section 222 or the separation section 224. This will be described below.

[0055] In recent years, with reduction in pixel size caused by increasing resolution of an image sensor, vignetting of obliquely incident light has become an issue. In a typical image sensor, in order to suppress an increase in sensitivity and color mixture, a separation section that separates a color filter for each pixel is provided; however, a decrease in sensitivity and a deterioration in color mixture occur due to the obliquely incident light striking the separation section.

[0056] In contrast, as described above, a structure has been proposed in which a plurality of waveguide wall parts each corresponding to a separation section is included and each of the plurality of waveguide wall parts is provided at a position subjected to pupil correction to thereby prevent the obliquely incident light from striking the separation section.

[0057] However, in a case where the pixel size is, for example, smaller than or equal to about a wavelength of the incident light, just increasing the number of layers does not allow the light to be narrowed due to a diffraction limit, and color mixture occurs due to striking of the light on the separation section, leakage of the light from a lower part of the separation section to adjacent pixels, and a component that guides the light in the separation section.

[0058] In contrast, in the present embodiment, the waveguide section 22 that is provided between the first surface 11S1 of the semiconductor substrate 11 and the lens layer 23 and includes the color filters and the separation sections has a multilayer structure (two layers, that is, the first layer 22A and the second layer 22B), and the separation sections 222 and 224 that respectively separate the color filter 221 of the first layer 22A and the color filter 223 of the second layer 22B are formed using materials having different refractive indices. This suppresses scattering of the oblique incident light L by the separation section 222 or the separation section 224.

[0059] Thus, in the photodetector 1 according to the present embodiment, it is possible to improve spectral characteristics.

[0060] Next, a description is given of a second embodiment and Modification Examples 1 to 7 of the present disclosure. Hereinafter, components similar to those of the embodiment described above are denoted by the same reference numerals, and descriptions thereof are omitted as appropriate. <2. Modification Examples> (2-1. Modification Example 1)

[0061] Fig. 9 schematically illustrates an example (a photodetector 2A) of a cross-sectional configuration of a photodetector according to Modification Example 1 of the present disclosure. Fig. 10 schematically illustrates another example (a photodetector 2B) of the cross-sectional configuration of the photodetector according to Modification Example 1 of the present disclosure. The photodetectors 2A and 2B are each, for example, a CMOS image sensor or the like included in an electronic apparatus such as a digital still camera or a video camera, and are each, for example, what is called a back-illuminated photodetector, as with the photodetector 1 according to the first embodiment described above.

[0062] In the first embodiment described above, an example has been described in which, of the separation sections 222, 224, and 226 of the plurality of layers (for example, the first layer 22A, the second layer 22B, and the third layer 22C) included in the waveguide section 22, the separation section having a low refractive index is formed using a low refractive index material such as silicon oxide (SiOx); however, the present embodiment is not limited thereto. In the present modification example, the separation section has an air gap G inside so as to have a low refractive index.

[0063] Fig. 9 illustrates a configuration in which, in a waveguide section 24 including three layers, that is, the first layer 22A, the second layer 22B, and a third layer 24C, a separation section 246 of the third layer 24C that is the uppermost layer has the air gap G inside. Fig. 10 illustrates a configuration in which, in the waveguide section 24 including three layers, that is, a first layer 24A, the second layer 22B, and the third layer 22C, a separation section 242 of the first layer 24A that is the lowermost layer has the air gap G inside. As with the first embodiment described above, the separation section having the air gap G inside is applicable to a layer in which light is desired to be narrowed (for example, the uppermost layer, the lowermost layer, or a layer provided between the uppermost layer and the lowermost layer) of a plurality of layers included in the waveguide section 24.

[0064] It is possible to form the separation section 242 having the air gap G inside in the first layer 24A as follows, for example.

[0065] First, as illustrated in Fig. 11A, a sacrificial layer 243 is formed on the protection layer 21 by photolithography and an etching technique. Thereafter, as illustrated in Fig. 11B, a passivation film 242A is formed on a top surface and a side surface of the sacrificial layer 243. Thereafter, as illustrated in Fig. 11C, the color filter 221 is formed to form the first layer 24A.

[0066] Thereafter, as illustrated in Fig. 11D, a coating layer 251 is formed on the first layer 24A. Thereafter, as illustrated in Fig. 11E, a through hole H that penetrates the coating layer 251 and the passivation film 242A is formed on the sacrificial layer 243 by photolithography and an etching technique. Thereafter, as illustrated in Fig. 11F, the sacrificial layer 243 is removed by etching. Thus, the separation section 242 having the air gap G inside is formed.

[0067] Thereafter, as illustrated in Fig. 11G, a closing layer 252 that closes the through hole H is formed on the coating layer 251. Thereafter, as illustrated in Fig. 11H, the separation section 224 is formed on the closing layer 252 by photolithography and an etching technique. Thereafter, as with the first embodiment described above, the color filter 223 is formed to form the second layer 22B, and the separation section 226 and the color filter 225 are formed in order on the second layer 22B to form the third layer 22C.

[0068] Thereafter, the lens layer 23 including the plurality of microlenses 23L is bonded onto the third layer 22C. Thus, for example, the photodetector 2B illustrated in Fig. 10 is completed.

[0069] As described above, in the present modification example, the waveguide section 24 that is provided between the first surface 11S1 of the semiconductor substrate 11 and the lens layer 23 and includes the color filters and the separation sections has a multilayer structure (for example, three layers), and any of the separation sections provided in the respective layers has the air gap inside so as to have a low refractive index. In such a configuration also, it is possible to achieve effects similar to those of the first embodiment described above. (2-2. Modification Example 2)

[0070] Fig.12 schematically illustrates an example (a photodetector 3A) of a cross-sectional configuration of a photodetector according to Modification Example 2 of the present disclosure. Fig. 13 schematically illustrates another example (a photodetector 3B) of the cross-sectional configuration of the photodetector according to Modification Example 2 of the present disclosure. The photodetectors 3A and 3B are each, for example, a CMOS image sensor or the like included in an electronic apparatus such as a digital still camera or a video camera, and are each, for example, what is called a back-illuminated photodetector, as with the photodetector 1 according to the first embodiment described above.

[0071] In the first embodiment described above, an example has been described in which, of the separation sections 222, 224, and 226 of the plurality of layers (for example, the first layer 22A, the second layer 22B, and the third layer 22C) included in the waveguide section 22, the separation section having a low refractive index is formed using a low refractive index material such as silicon oxide (SiOx); however, the present embodiment is not limited thereto. In the present modification example, the separation section includes a metal material having a light absorption property with a low refractive index.

[0072] Fig. 12 illustrates a separation section 262 including the metal material having the light absorption property of a first layer 26A that is the lowermost layer in a waveguide section 26 including three layers, that is, the first layer 26A, the second layer 22B, and the third layer 22C. Fig. 13 illustrates a separation section 266 including the metal material having the light absorption property of a third layer 26C that is the uppermost layer in the waveguide section 26 including three layers, that is, the first layer 22A, the second layer 22B, and the third layer 26C. As with the first embodiment described above, the separation section formed using the metal material having the light absorption property is applicable to a layer in which light is desired to be narrowed (for example, the uppermost layer, the lowermost layer, or a layer provided between the uppermost layer and the lowermost layer) of a plurality of layers included in the waveguide section 26.

[0073] Examples of the metal material having the light absorption property include tungsten (W), titanium (Ti), and titanium nitride (TiN).

[0074] As described above, in the present modification example, the waveguide section 26 that is provided between the first surface 11S1 of the semiconductor substrate 11 and the lens layer 23 and includes the color filters and the separation sections has a multilayer structure (for example, three layers), and any of the separation sections provided in the respective layers includes the metal material having the light absorption property to have a low refractive index. Accordingly, it is possible to prevent leakage to the adjacently arranged unit pixels P by the separation section (for example, the separation section 262 or the separation section 266). Thus, it is possible to achieve effects similar to those of the first embodiment described above. (2-3. Modification Example 3)

[0075] Fig. 14 schematically illustrates an example of a cross-sectional configuration of a photodetector (a photodetector 4) according to Modification Example 3 of the present disclosure. The photodetector 4 is, for example, a CMOS image sensor or the like included in an electronic apparatus such as a digital still camera or a video camera, and is, for example, what is called a back-illuminated photodetector, as with the photodetector 1 according to the first embodiment described above.

[0076] In the first embodiment described above, an example has been described in which all of the separation sections 222, 224, and 226 of the plurality of layers (for example, the first layer 22A, the second layer 22B, and the third layer 22C) included in the waveguide section 22 are formed to have the same width; however, the present embodiment is not limited thereto. In the present modification example, the separation sections 222, 224, and 226 are formed so that the width is narrower in upper layers (w1 > w2 > w3).

[0077] As described above, in the present modification example, the separation sections 222, 224, and 226 are formed so that the width is narrower in upper layers (w1 > w2 > w3). This further suppresses scattering of the obliquely incident light L by the separation sections 222, 224, and 226. Accordingly, it is possible to further improve the spectral characteristic. (2-4. Modification Example 4)

[0078] Fig. 15 schematically illustrates an example of a cross-sectional configuration of a photodetector (a photodetector 5) according to Modification Example 4 of the present disclosure. The photodetector 5 is, for example, a CMOS image sensor or the like included in an electronic apparatus such as a digital still camera or a video camera, and is, for example, what is called a back-illuminated photodetector, as with the photodetector 1 according to the first embodiment described above.

[0079] In the first embodiment described above, an example has been described in which all of the plurality of layers (for example, the first layer 22A, the second layer 22B, and the third layer 22C) included in the waveguide section 22 are formed to have the same thickness; however, the present embodiment is not limited thereto. In the present modification example, the first layer 22A, the second layer 22B, and the third layer 22C are formed so that the thickness is thinner in upper layers (h1 > h2 > h3).

[0080] As described above, in the present modification example, the plurality of layers (for example, the first layer 22A, the second layer 22B, and the third layer 22C) included in the waveguide section 22 are formed to be thinner in upper layers. This further suppresses scattering of the obliquely incident light l by the separation sections 222, 224, and 226. Accordingly, it is possible to further improve the spectral characteristic. (2-5. Modification Example 5)

[0081] Fig. 16 schematically illustrates an example (a photodetector 6A) of a cross-sectional configuration of a photodetector according to Modification Example 5 of the present disclosure. Fig. 17 schematically illustrates another example (a photodetector 6B) of the cross-sectional configuration of the photodetector according to Modification Example 5 of the present disclosure. Fig. 18 schematically illustrates another example (a photodetector 6C) of the cross-sectional configuration of the photodetector according to Modification Example 5 of the present disclosure. The photodetectors 6A, 6B, and 6C are each, for example, a CMOS image sensor or the like included in an electronic apparatus such as a digital still camera or a video camera, and are each, for example, what is called a back-illuminated photodetector, as with the photodetector 1 according to the first embodiment described above.

[0082] In the first embodiment described above, an example has been described in which the separation sections 222, 224, and 226 are provided between every adjacent unit pixels P each provided with color filters different from each other as color filters; however, the present embodiment is not limited thereto. For example, in a case where scattering due to vignetting of light causes color mixture, a part of the separation sections may be omitted.

[0083] Fig. 16 illustrates the waveguide section 22 that includes three layers, that is, the first layer 22A, the second layer 22B, and the third layer 22C and in which a part (for example, the separation section 226 between a red pixel Pr provided with a red filter 225R and a green pixel Pg provided with a green filter 225G adjacent to the red pixel Pr on light incident side) of the separation sections 226 of the third layer 22C that is the uppermost layer is omitted. Fig. 17 illustrates the waveguide section 22 that includes three layers, that is, the first layer 22A, the second layer 22B, and the third layer 22C and in which a part (for example, the separation section 222 between the red pixel Pr provided with a red filter 221R and a blue pixel Pb provided with a blue filter 221B adjacent to the red pixel Pr on side opposite to the light incident side) of the separation sections 222 of the first layer 22A that is the lowermost layer is omitted.

[0084] Light having a long wavelength is not easily refracted; therefore, obliquely incident light is condensed with being further angled.

[0085] Accordingly, in the present modification example, a separation section adjacent to the red pixel Pr is omitted as appropriate. The red pixel Pr detects red light (R) having the longest wavelength among the red light (R), green light (G), and blue light (B). This makes it possible to reduce scattering of a red light component scattered by striking the separation section (for example, the separation section 222 or the separation section 224). Accordingly, it is possible to further improve the spectral characteristic.

[0086] Fig. 18 illustrates the waveguide section 22 that includes three layers, that is, the first layer 22A, the second layer 22B, and the third layer 22C and in which the separation section 224 of the second layer 22B contributing less to a light-condensing property is omitted.

[0087] As described above, in the present modification example, of the plurality of layers (for example, the first layer 22A, the second layer 22B, and the third layer 22C) included in the waveguide section 22, the separation section (for example, the separation section 224) of a layer contributing less to the light-condensing property is omitted. Accordingly, it is possible to simplify a manufacturing process in addition to the effects of the first embodiment described above. (2-6. Modification Example 6)

[0088] Fig. 19 schematically illustrates an example of a cross-sectional configuration of a photodetector (a photodetector 7) according to Modification Example 6 of the present disclosure. The photodetector 7 is, for example, a CMOS image sensor or the like included in an electronic apparatus such as a digital still camera or a video camera, and is, for example, what is called a back-illuminated photodetector, as with the photodetector 1 according to the first embodiment described above.

[0089] For example, a separation section 274 of a second layer 27B of a plurality of layers included in a waveguide section 27 may be configured to have a antireflection function.

[0090] It is possible to form the separation section 274, for example, as a stacked film in which an insulating film having a high refractive index and an insulating film having a low refractive index are stacked in this order. It is possible to form the insulating film having a high refractive index using, for example, a material having a refractive index of 1.8 to 2.5 such as silicon nitride (Si3N4), titanium oxide (TiO2), tantalum oxide (Ta2O5), zirconium oxide (ZrO2), niobium oxide (Nb2O5), hafnium oxide (HfO2), or aluminum oxide (Al2O3). It is possible to form the insulating film having a low refractive index using, for example, a material such as silicon dioxide (SiO2), silicon oxynitride (SiON), or silicon oxycarbide (SiOC).

[0091] As described above, in the present modification example, of the plurality of layers included in the waveguide section 27, for example, the second layer 27B that is an intermediate layer is provided with the separation section 274 having the antireflection function. Accordingly, it is possible to enhance an antireflection effect with respect to the adjacent color filter 223. Thus, it is possible to further improve the spectral characteristic. (2-7. Modification Example 7)

[0092] Fig. 20 schematically illustrates an example (a photodetector 1A) of a cross-sectional configuration of a photodetector according to Modification Example 7 of the present disclosure.

[0093] In the first embodiment described above, an example has been described in which the plurality of layers (for example, the first layer 22A, the second layer 22B, and the third layer 22C) included in the waveguide section 22 are directly stacked. However, protection layers 281, 282, and 283 may be provided respectively between the first layer 22A and the second layer 22B, between the second layer 22B and the third layer 22C, and between the third layer 22C and the lens layer 23.

[0094] Fig. 21 schematically illustrates another example (a photodetector 1B) of the cross-sectional configuration of the photodetector according to Modification Example 7 of the present disclosure.

[0095] In the first embodiment described above, an example has been described in which the color filters and the microlens 23L are provided for each unit pixel P. However, the color filters and the microlens 23L may be provided to extend over a plurality of unit pixels P.

[0096] The photodetector 1B is configured to acquire imaging information and parallax information. An imaging pixel photoelectrically converts, in the photodiode PD, a subject image formed as an image by an imaging lens, to generate a signal for image generation. An imaging-plane phase-difference pixel divides a pupil region of the imaging lens, and photoelectrically converts a subject image from the divided pupil region, to generate a signal for phase-difference detection. <3. Second Embodiment>

[0097] Fig. 22 schematically illustrates an example of a cross-sectional configuration of a photodetector (a photodetector 8) according to a second embodiment of the present disclosure. The photodetector 8 is, for example, a CMOS image sensor or the like included in an electronic apparatus such as a digital still camera or a video camera, and includes, as an imaging area, a pixel section (the pixel section 100A) including a plurality of pixels two-dimensionally arranged in a matrix. The photodetector 8 is, for example, what is called a back-illuminated photodetector in the CMOS image sensor or the like.Configuration of Photodetector

[0098] The photodetector 8 has the first surface 11S1 and the second surface 11S2 opposed to each other and includes a waveguide section 42 and the lens layer 23 in this order on the first surface 11S1 of the semiconductor substrate 11. The semiconductor substrate 11 includes the plurality of photoelectric conversion sections 12 arranged in an array in the in-plane direction of the XY plane. The waveguide section 42 includes a plurality of layers (for example, two layers, that is, a first layer 42A and a second layer 42B), and the plurality of layers each includes a corresponding one of color filters 421 and 423, and a corresponding one of separation sections 422 and 424 that respectively separate the color filters 421 and 423. The separation sections 422 and 424 each have the air gap G inside.Method 1 of Manufacturing Waveguide Section

[0099] It is possible to form the waveguide section 42 of the photodetector 8 as follows, for example.

[0100] First, as illustrated in Fig. 23A, a light-blocking film 44 and a sacrificial layer 425 including, for example, amorphous silicon are formed in order on the protection layer 21, and thereafter, a resist film 441 is patterned on the sacrificial layer 425 by a photolithography technique. Thereafter, as illustrated in Fig. 23B, sacrificial layer 425 and the light-blocking film 44 are processed by etching. Thereafter, as illustrated in Fig. 23C, a passivation film 422A is formed so as to cover a top surface and a side surface of the sacrificial layer 425.

[0101] Thereafter, as illustrated in Fig. 23D, the color filter 421 is formed to form the first layer 42A. Thereafter, as illustrated in Fig. 23E, a coating layer 431 is formed on the first layer 42A. Thereafter, as illustrated in Fig. 23F, a resist film 442 is patterned on the coating layer 431 by a photolithography technique.

[0102] Thereafter, as illustrated in Fig. 23G, a through hole that penetrates the coating layer 431 and the passivation film 422A is formed on the sacrificial layer 425 by an etching technique. Thereafter, as illustrated in Fig. 23H, a sacrificial layer 425 is further formed on the coating layer 431, and thereafter, a resist film 443 is patterned on the sacrificial layer 425 by a photolithography technique. Thereafter, as illustrated in Fig. 23I, the sacrificial layer 425 is processed by etching.

[0103] Thereafter, as illustrated in Fig. 23J, a passivation film 424A is formed so as to cover a top surface and a side surface of the sacrificial layer 425. Thereafter, as illustrated in Fig. 23K, the color filter 423 is formed to form the second layer 42B. Thereafter, as illustrated in Fig. 23L, a coating layer 432 is formed on the second layer 42B, and thereafter, a resist film 442 is patterned on the coating layer 432 by a photolithography technique. Thereafter, the sacrificial layer 425 is removed by etching. Thus, the air gap G is formed in each of the separation sections 422 and 424 of the first layer 42A and the second layer 42B.

[0104] Thereafter, the lens layer 23 including the plurality of microlenses 23L is bonded onto the second layer 42B. Thus, for example, the photodetector 8 illustrated in Fig. 20 is completed.Method 2 of Manufacturing Waveguide Section

[0105] It is possible to form the air gap G in each of the layers 42A and 42B in the waveguide section 42 of the photodetector 8 as follows, for example.

[0106] First, as illustrated in Fig. 24A, as with the manufacturing method 1 described above, the resist film 442 is patterned on the coating layer 431 by a photolithography technique. Thereafter, as illustrated in Fig. 24B, a through hole that penetrates the coating layer 431 and the passivation film 422A is formed on the sacrificial layer 425 by an etching technique, and thereafter, the sacrificial layer 425 is removed by etching. Thus, the air gap G is formed in the separation section 422 of the first layer 42A.

[0107] Thereafter, as illustrated in Fig. 24C, the sacrificial layer 425 is formed on the coating layer 431, and thereafter, the resist film 443 is patterned on the sacrificial layer 425 by a photolithography technique. Thereafter, as illustrated in Fig. 24D, the sacrificial layer 425 is processed by etching, and thereafter, the passivation film 424A is formed so as to cover the top surface and the side surface of the sacrificial layer 425. Thereafter, as illustrated in Fig. 24E, the color filter 423 is formed to form the second layer 42B. Thereafter, as illustrated in Fig. 24F, the coating layer 432 is formed on the second layer 42B, and thereafter, the resist film 442 is patterned on the coating layer 432 by a photolithography technique. Thereafter, the sacrificial layer 425 is removed by etching. Thus, the air gap G is formed in the separation section 424 of the second layer 42B.

[0108] Thereafter, the lens layer including the plurality of microlenses 23L is bonded onto the second layer 42B. Thus, for example, the photodetector 8 illustrated in Fig. 22 is completed. <Workings and Effects>

[0109] In the photodetector 8 according to the present embodiment, the waveguide section 42 including the plurality of layers is provided between the first surface 11S1 of the semiconductor substrate 11 and the lens layer 23. The semiconductor substrate 11 includes the plurality of photoelectric conversion sections 12 arranged in an array in the in-plane direction of the XY plane. The lens layer 23 includes the plurality of microlenses 23L that is each provided for each unit pixel P, for example. The respective layers (for example, the first layer 42A and the second layer 42B) included in the waveguide section 42 each include a corresponding one of the color filters 421 and 423 and a corresponding one of the separation sections 422 and 424 that respectively separate the color filters 421 and 423. The separation sections 422 and 424 each have the air gap G inside. This increases a refractive index difference between the color filter 421 and the separation section 422 and a refractive index difference between the color filter 423 and the separation section 424.

[0110] Thus, in the photodetector 8 according to the present embodiment, it is possible to improve sensitivity. <4. Application Example> (Application Example 1)

[0111] The photodetector 1 described above or the like is applicable to any type of electronic apparatus with an imaging function. Examples of the electronic apparatus include camera systems such as digital still cameras and video cameras and mobile phones having the imaging functions. Fig. 25 illustrates a schematic configuration of an electronic apparatus 1000.

[0112] The electronic apparatus 1000 includes, for example, a lens group 1001, the photodetector 1, a Digital Signal Processor (DSP) circuit 1002, a frame memory 1003, a display section 1004, a storage section 1005, an operation section 1006, and a power supply section 1007. They are coupled to each other through a bus line 1008.

[0113] The lens group 1001 takes in incident light (image light) from a subject and forms an image on an imaging plane of the photodetector 1. The photodetector 1 converts a light amount of incident light formed as an image on the imaging plane by the lens group 1001 into electrical signals in units of pixels and supplies the electric signals as pixel signals to the DSP circuit 1002.

[0114] The DSP circuit 1002 is a signal processing circuit that processes signals supplied from the photodetector 1. The DSP circuit 1002 outputs image data obtained by processing the signals from the photodetector 1. The frame memory 1003 temporarily holds the image data processed by the DSP circuit 1002 in frame units.

[0115] The display section 1004 includes, for example, a panel-type display device such as a liquid crystal panel or an organic Electro Luminescence (EL) panel, and the storage section 1005 records image data of a moving image or a still image captured by the photodetector 1 on a recording medium such as a semiconductor memory or a hard disk.

[0116] The operation section 1006 outputs an operation signal concerning various functions of the electronic apparatus 1000 in accordance with an operation by a user. The power supply section 1007 supplies the DSP circuit 1002, the frame memory 1003, the display section 1004, the storage section 1005, and the operation section 1006 with various types of power as power for operating these supply targets as appropriate. (Application Example 2)

[0117] Fig. 26A schematically illustrates an example of an overall configuration of a photodetection system 2000 including the photodetector 1. Fig. 26B illustrates an example of a circuit configuration of the photodetection system 2000. The photodetection system 2000 includes a light-emitting device 2001 as a light source section that emits infrared light L2, and a photodetector 2002 as a light-receiving section including a photoelectric conversion element. As the photodetector 2002, it is possible to use the photodetector 1 described above. The photodetection system 2000 may further include a system controller 2003, a light source driving section 2004, a sensor controller 2005, a light source-side optical system 2006, and a camera-side optical system 2007.

[0118] The photodetector 2002 is able to detect light L1 and light L2. The light L1 is ambient light from outside reflected by a subject (a measurement object) 2100 (Fig. 26A). The light L2 is light emitted from the light-emitting device 2001 and then reflected by the subject 2100. The light L1 is, for example, visible light, and the light L2 is, for example, infrared light. The light L1 is detectable by a photoelectric conversion section in the photodetector 2002 and the light L2 is detectable by a photoelectric conversion region in the photodetector 2002. It is possible to obtain image information of the subject 2100 from the light L1 and obtain distance information between the subject 2100 and the photodetection system 2000 from the light L2. It is possible to mount the photodetection system 2000 on, for example, an electronic apparatus such as a smartphone and a mobile body such as a car. It is possible to configure the light-emitting device 2001 with, for example, a semiconductor laser, a surface-emitting semiconductor laser, or a vertical cavity surface emitting laser (VCSEL). As a method of detecting the light L2 emitted from the light-emitting device 2001 by the photodetector 2002, for example, it is possible to adopt an i Time-of-Flight (TOF) method; however, the method is not limited thereto. In the iTOF method, the photoelectric conversion section is able to measure a distance to the subject 2100 by TOF, for example. As a method of detecting the light L2 emitted from the light-emitting device 2001 by the photodetector 2002, it is possible to adopt, for example, a structured light method or a stereovision method. For example, in the structured light method, light having a predetermined pattern is projected on the subject 2100, and distortion of the pattern is analyzed, thereby making it possible to measure the distance between the photodetection system 2000 and the subject 2100. In addition, in the stereovision method, for example, two or more cameras are used to obtain two or more images of the subject 2100 viewed from two or more different viewpoints, thereby making it possible to measure the distance between the photodetection system 2000 and the subject 2100. It is to be noted that it is possible to synchronously control the light-emitting device 2001 and the photodetector 2002 by the system controller 2003. <5. Practical Application Examples> (Practical Application Example to Endoscopic Surgery System)

[0119] The technology according to the present disclosure (present technology) is applicable to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

[0120] Fig. 27 is a view depicting an example of a schematic configuration of an endoscopic surgery system to which the technology according to an embodiment of the present disclosure (present technology) can be applied.

[0121] In Fig. 27, a state is illustrated in which a surgeon (medical doctor) 11131 is using an endoscopic surgery system 11000 to perform surgery for a patient 11132 on a patient bed 11133. As depicted, the endoscopic surgery system 11000 includes an endoscope 11100, other surgical tools 11110 such as a pneumoperitoneum tube 11111 and an energy device 11112, a supporting arm apparatus 11120 which supports the endoscope 11100 thereon, and a cart 11200 on which various apparatus for endoscopic surgery are mounted.

[0122] The endoscope 11100 includes a lens barrel 11101 having a region of a predetermined length from a distal end thereof to be inserted into a body cavity of the patient 11132, and a camera head 11102 connected to a proximal end of the lens barrel 11101. In the example depicted, the endoscope 11100 is depicted which includes as a rigid endoscope having the lens barrel 11101 of the hard type. However, the endoscope 11100 may otherwise be included as a flexible endoscope having the lens barrel 11101 of the flexible type.

[0123] The lens barrel 11101 has at a distal end thereof, an opening in which an objective lens is fitted. A light source apparatus 11203 is connected to the endoscope 11100 such that light generated by the light source apparatus 11203 is introduced to a distal end of the lens barrel 11101 by a light guide extending in the inside of the lens barrel 11101 and is irradiated toward an observation target in a body cavity of the patient 11132 through the objective lens. It is to be noted that the endoscope 11100 may be a forward-viewing endoscope or may be an oblique-viewing endoscope or a side-viewing endoscope.

[0124] An optical system and an image pickup element are provided in the inside of the camera head 11102 such that reflected light (observation light) from the observation target is condensed on the image pickup element by the optical system. The observation light is photo-electrically converted by the image pickup element to generate an electric signal corresponding to the observation light, namely, an image signal corresponding to an observation image. The image signal is transmitted as raw data to a camera control unit (CCU) 11201.

[0125] The CCU 11201 includes a central processing unit (CPU), a graphics processing unit (GPU) or the like and integrally controls operation of the endoscope 11100 and a display apparatus 11202. Further, the CCU 11201 receives an image signal from the camera head 11102 and performs, for the image signal, various image processes for displaying an image based on the image signal such as, for example, a development process (demosaic processing).

[0126] The display apparatus 11202 displays thereon an image based on an image signal, for which the image processes have been performed by the CCU 11201, under the control of the CCU 11201.

[0127] The light source apparatus 11203 includes a light source such as, for example, a light emitting diode (LED) and supplies irradiation light upon imaging of a surgical region to the endoscope 11100.

[0128] An inputting apparatus 11204 is an input interface for the endoscopic surgery system 11000. A user can perform inputting of various kinds of information or instruction inputting to the endoscopic surgery system 11000 through the inputting apparatus 11204. For example, the user would input an instruction, or a like, to change an image pickup condition (type of irradiation light, magnification, focal distance or the like) by the endoscope 11100.

[0129] A treatment tool controlling apparatus 11205 controls driving of the energy device 11112 for cautery or incision of a tissue, sealing of a blood vessel, or the like. A pneumoperitoneum apparatus 11206 feeds gas into a body cavity of the patient 11132 through the pneumoperitoneum tube 11111 to inflate the body cavity in order to secure the field of view of the endoscope 11100 and secure the working space for the surgeon. A recorder 11207 is an apparatus capable of recording various kinds of information relating to surgery. A printer 11208 is an apparatus capable of printing various kinds of information relating to surgery in various forms such as a text, an image or a graph.

[0130] It is to be noted that the light source apparatus 11203 which supplies irradiation light when a surgical region is to be imaged to the endoscope 11100 may include a white light source which includes, for example, an LED, a laser light source or a combination of them. Where a white light source includes a combination of red, green, and blue (RGB) laser light sources, since the output intensity and the output timing can be controlled with a high degree of accuracy for each color (each wavelength), adjustments to the white balance of a pick-up image can be performed by the light source apparatus 11203. Further, in this case, if laser beams from the respective RGB laser light sources are irradiated time-divisionally on an observation target and driving of the image pickup elements of the camera head 11102 are controlled in a synchronous manner with the irradiation timings. Then images individually corresponding to the R, G and B colors can be also picked up in a time division manner. According to this method, a color image can be obtained even if color filters are not provided for the image pick-up element.

[0131] Further, the light source apparatus 11203 may be controlled such that the intensity of light to be output is changed for each predetermined time. By controlling the driving of the image pickup element of the camera head 11102 in synchronism with the timing of the change of the intensity of light to acquire images time-divisionally and synthesizing the images, an image of a high dynamic range free from underexposed blocked up shadows and overexposed highlights can be created.

[0132] Further, the light source apparatus 11203 may be configured to supply light of a predetermined wavelength band ready for special light observation. In special light observation, for example, by utilizing the wavelength dependency of absorption of light in a body tissue to irradiate light of a narrow band in comparison with irradiation light upon ordinary observation (namely, white light), narrow band observation (narrow band imaging) of imaging a predetermined tissue such as a blood vessel of a superficial portion of the mucous membrane or the like in a high contrast is performed. Alternatively, in special light observation, fluorescent observation for obtaining an image from fluorescent light generated by irradiation of excitation light may be performed. In fluorescent observation, it is possible to perform observations of fluorescent light from a body tissue by irradiating excitation light on the body tissue (autofluorescence observation) or to obtain a fluorescent light image by locally injecting a reagent such as indocyanine green (ICG) into a body tissue and irradiating excitation light corresponding to a fluorescent light wavelength of the reagent upon the body tissue. The light source apparatus 11203 can be configured to supply such narrow-band light and / or excitation light suitable for special light observation as described above.

[0133] Fig. 28 is a block diagram depicting an example of a functional configuration of the camera head 11102 and the CCU 11201 depicted in Fig. 27.

[0134] The camera head 11102 includes a lens unit 11401, an image pickup unit 11402, a driving unit 11403, a communication unit 11404 and a camera head controlling unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412 and a control unit 11413. The camera head 11102 and the CCU 11201 are connected for communication to each other by a transmission cable 11400.

[0135] The lens unit 11401 is an optical system, provided at a connecting location to the lens barrel 11101. Observation light taken in from a distal end of the lens barrel 11101 is guided to the camera head 11102 and introduced into the lens unit 11401. The lens unit 11401 includes a combination of a plurality of lenses including a zoom lens and a focusing lens.

[0136] The number of image pick-up elements which is included by the image pick-up unit 11402 may be one (single-plate type) or a plural number (multi-plate type). Where the image pick-up unit 11402 is configured as that of the multi-plate type, for example, image signals corresponding to respective R, G and B are generated by the image pick-up elements, and the image signals may be synthesized to obtain a color image. The image pick-up unit 11402 may also be configured so as to have a pair of image pickup elements for acquiring respective image signals for the right eye and the left eye ready for three- dimensional (3D) display. If 3D display is performed, then the depth of a living body tissue in a surgical region can be comprehended more accurately by the surgeon 11131. It is to be noted that, where the image pickup unit 11402 is configured as that of a stereoscopic type, a plurality of systems of lens units 11401 are provided corresponding to the individual image pick-up elements.

[0137] Further, the image pick-up unit 11402 may not necessarily be provided on the camera head 11102. For example, the image pick-up unit 11402 may be provided immediately behind the objective lens in the inside of the lens barrel 11101.

[0138] The driving unit 11403 includes an actuator and moves the zoom lens and the focusing lens of the lens unit 11401 by a predetermined distance along an optical axis under the control of the camera head controlling unit 11405. Consequently, the magnification and the focal point of a picked-up image by the image pickup unit 11402 can be suitably adjusted.

[0139] The communication unit 11404 includes a communication apparatus for transmitting and receiving various kinds of information to and from the CCU 11201. The communication unit 11404 transmits an image signal acquired from the image pickup unit 11402 as raw data to the CCU 11201 through the transmission cable 11400.

[0140] In addition, the communication unit 11404 receives a control signal for driving the camera head 11102 from the CCU 11201 and supplies the control signal to the camera head controlling unit 11405. The control signal includes information relating to image pickup conditions such as, for example, information that a frame rate of a picked-up image is designated, information that an exposure value upon image pick-up is designated and / or information that a magnification and a focal point of a picked up image are designated.

[0141] It is to be noted that the image pick-up conditions such as the frame rate, exposure value, magnification or focal point may be designated by the user or may be set automatically by the control unit 11413 of the CCU 11201 based on an acquired image signal. In the latter case, an auto exposure (AE) function, an auto focus (AF) function and an auto white balance (AWB) function are incorporated in the endoscope 11100.

[0142] The camera head controlling unit 11405 controls driving of the camera head 11102 based on a control signal from the CCU 11201 received through the communication unit 11404.

[0143] The communication unit 11411 includes a communication apparatus for transmitting and receiving various kinds of information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted thereto from the camera head 11102 through the transmission cable 11400.

[0144] Further, the communication unit 11411 transmits a control signal for driving of the camera head 11102 to the camera head 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication or the like.

[0145] The image processing unit 11412 performs various image processes for an image signal in the form of raw data transmitted thereto from the camera head 11102.

[0146] The control unit 11413 performs various kinds of control processes relating to image pick-up of a surgical region, or the like, by the endoscope 11100 and display of the picked-up image, or the like. For example, the control unit 11413 creates a control signal for driving of the camera head 11102.

[0147] Further, the control unit 11413 controls, based on an image signal for which image processes have been performed by the image processing unit 11412, the display apparatus 11202 to display a picked-up image in which the surgical region or the like is imaged. Thereupon, the control unit 11413 may recognize various objects in the picked-up image using various image recognition technologies. For example, the control unit 11413 can recognize a surgical tool such as forceps, a particular living body region, bleeding, mist when the energy device 11112 is used and so forth by detecting the shape, color and so forth of edges of objects included in a picked-up image. The control unit 11413 may cause, controlling the display apparatus 11202 to display a picked-up image, various kinds of surgery supporting information to be displayed in an overlapping manner with an image of the surgical region using a result of the recognition. Where surgery supporting information is displayed in an overlapping manner and presented to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery with certainty.

[0148] The transmission cable 11400 which connects the camera head 11102 and the CCU 11201 to each other is an electric signal cable ready for communication of an electric signal, an optical fiber ready for optical communication or a composite cable ready for both electrical and optical communications.

[0149] Here, while, in the example depicted, communication is performed by wired communication using the transmission cable 11400, the communication between the camera head 11102 and the CCU 11201, however, may be performed by wireless communication.

[0150] One example of the endoscopic surgery system to which the technology according to the present disclosure is applicable has been described above. The technology according to the present disclosure is applicable to, for example, the image pick-up unit 11402 of the configurations described above. Applying the technology according to the present disclosure to the image pick-up unit 11402 makes it possible to improve detection accuracy.

[0151] It is to be noted that the endoscopic surgery system has been described here as an example, but the technology according to the present disclosure may be additionally applied to, for example, a microscopic surgery system and the like. (Practical Application Example to Mobile Body)

[0152] The technology according to the present disclosure is applicable to various products. For example, the technology according to the present disclosure may be achieved in the form of an apparatus to be mounted to a mobile body of any kind such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility, an airplane, a drone, a vessel, a robot, a construction machine, or an agricultural machine (tractor).

[0153] Fig. 29 is a block diagram depicting an example of a schematic configuration of a vehicle control system as an example of a mobile body control system to which the technology according to an embodiment of the present disclosure can be applied.

[0154] The vehicle control system 12000 includes a plurality of electronic control units connected to each other via a communication network 12001. In the example depicted in Fig. 29, the vehicle control system 12000 includes a driving system control unit 12010, a body system control unit 12020, an outside-vehicle information detecting unit 12030, an in-vehicle information detecting unit 12040, and an integrated control unit 12050. In addition, a microcomputer 12051, a sound / image output section 12052, and a vehicle-mounted network interface (I / F) 12053 are illustrated as a functional configuration of the integrated control unit 12050.

[0155] The driving system control unit 12010 controls the operation of devices related to the driving system of the vehicle in accordance with various kinds of programs. For example, the driving system control unit 12010 functions as a control device for a driving force generating device for generating the driving force of the vehicle, such as an internal combustion engine, a driving motor, or the like, a driving force transmitting mechanism for transmitting the driving force to wheels, a steering mechanism for adjusting the steering angle of the vehicle, a braking device for generating the braking force of the vehicle, and the like.

[0156] The body system control unit 12020 controls the operation of various kinds of devices provided to a vehicle body in accordance with various kinds of programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various kinds of lamps such as a headlamp, a backup lamp, a brake lamp, a turn signal, a fog lamp, or the like. In this case, radio waves transmitted from a mobile device as an alternative to a key or signals of various kinds of switches, can be input to the body system control unit 12020. The body system control unit 12020 receives these input radio waves or signals, and controls a door lock device, the power window device, the lamps, or the like, of the vehicle.

[0157] The outside-vehicle information detecting unit 12030 detects information about the outside of the vehicle including the vehicle control system 12000. For example, the outside-vehicle information detecting unit 12030 is connected with an imaging section 12031. The outside-vehicle information detecting unit 12030 instructs the imaging section 12031 to provide an image of the outside of the vehicle and then receives the imaged image from the imaging section 12031. Based on the received image, the outside-vehicle information detecting unit 12030 processes the received image to detect objects such as a human, a vehicle, an obstacle, a sign, a character on a road surface, or the like, or processes the received image to detect distances from the object.

[0158] The imaging section 12031 is an optical sensor that receives light, and which outputs an electrical signal corresponding to a received amount of light. The imaging section 12031 can output the electrical signal as an image or can output the electrical signal as information about a measured distance. In addition, the light received by the imaging section 12031 may be visible light or may be invisible light such as infrared rays or the like.

[0159] The in-vehicle information detecting unit 12040 detects information about the inside of the vehicle. The in-vehicle information detecting unit 12040 is, for example, connected with a driver state detecting section 12041 that detects the state of a driver. The driver state detecting section 12041, for example, includes a camera that images the driver. Based on the detection information input from the driver state detecting section 12041, the in-vehicle information detecting unit 12040 may calculate a degree of fatigue of the driver or a degree of concentration of the driver or may determine whether the driver is dozing.

[0160] The microcomputer 12051 can calculate a control target value for the driving force generating device, the steering mechanism, or the braking device based on the information about the inside or outside of the vehicle obtained by the outside-vehicle information detecting unit 12030 or the in-vehicle information detecting unit 12040 and output a control command to the driving system control unit 12010. For example, the microcomputer 12051 can perform cooperative control intended to implement functions of an advanced driver assistance system (ADAS) which functions include collision avoidance or shock mitigation for the vehicle, following driving based on a following distance, vehicle speed maintaining driving, a warning of collision of the vehicle, a warning of deviation of the vehicle from a lane, or the like.

[0161] In addition, the microcomputer 12051 can perform cooperative control intended for automated driving, (e.g., operating the vehicle) without input from the driver, or the like), by controlling the driving force generating device, the steering mechanism, the braking device, or the like based on the information about the outside or the inside of the vehicle obtained by the outside-vehicle information detecting unit 12030 or the in-vehicle information detecting unit 12040.

[0162] In addition, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information about the outside of the vehicle obtained by the outside-vehicle information detecting unit 12030. For example, the microcomputer 12051 can perform cooperative control intended to prevent a glare by controlling the headlamp to change from a high beam to a low beam, for example, in accordance with the position of a preceding vehicle or an oncoming vehicle detected by the outside-vehicle information detecting unit 12030.

[0163] The sound / image output section 12052 transmits an output signal of at least one of a sound and an image to an output device capable of visually or auditorily notifying information to an occupant of the vehicle or the outside of the vehicle. In the example of Fig. 29, an audio speaker 12061, a display section 12062, and an instrument panel 12063 are illustrated as the output device. The display section 12062 may, for example, include at least one of an on-board display and a head-up display.

[0164] Fig. 30 is a diagram depicting an example of the installation position of the imaging section 12031.

[0165] In Fig. 30, the imaging section 12031 includes imaging sections 12101, 12102, 12103, 12104, and 12105.

[0166] The imaging sections 12101, 12102, 12103, 12104, and 12105 are, for example, disposed at positions on a front nose, sideview mirrors, a rear bumper, and a back door of the vehicle 12100 as well as a position on an upper portion of a windshield within the interior of the vehicle. The imaging section 12101 provided to the front nose and the imaging section 12105 provided to the upper portion of the windshield within the interior of the vehicle, obtain mainly an image of the front of the vehicle 12100. The imaging sections 12102 and 12103 provided to the sideview mirrors obtain mainly an image of the sides of the vehicle 12100. The imaging section 12104 provided to the rear bumper or the back door, obtains mainly an image of the rear of the vehicle 12100. The imaging section 12105 provided to the upper portion of the windshield within the interior of the vehicle is used mainly to detect a preceding vehicle, a pedestrian, an obstacle, a signal, a traffic sign, a lane, or the like.

[0167] Incidentally, Fig. 30 depicts an example of photographing ranges of the imaging sections 12101 to 12104. An imaging range 12111 represents the imaging range of the imaging section 12101 provided to the front nose. Imaging ranges 12112 and 12113 respectively represent the imaging ranges of the imaging sections 12102 and 12103 provided to the sideview mirrors. An imaging range 12114 represents the imaging range of the imaging section 12104 provided to the rear bumper or the back door. A bird’s-eye image of the vehicle 12100 as viewed from above is obtained by superimposing image data imaged by the imaging sections 12101 to 12104, for example.

[0168] At least one of the imaging sections 12101 to 12104 may have a function of obtaining distance information. For example, at least one of the imaging sections 12101 to 12104 may be a stereo camera constituted of a plurality of imaging elements or may be an imaging element having pixels for phase difference detection.

[0169] For example, the microcomputer 12051 can determine a distance to each three-dimensional object within the imaging ranges 12111 to 12114 and a temporal change in the distance (relative speed with respect to the vehicle 12100) on the basis of the distance information obtained from the imaging sections 12101 to 12104, and thereby extract, as a preceding vehicle, a nearest three-dimensional object in particular that is present on a traveling path of the vehicle 12100 and which travels in substantially the same direction as the vehicle 12100 at a predetermined speed (for example, equal to or more than 0 km / hour). Further, the microcomputer 12051 can set a following distance to be maintained in front of a preceding vehicle in advance and perform automatic brake control (including following stop control), automatic acceleration control (including following start control), or the like. It is thus possible to perform cooperative control intended for automated driving that allows the vehicle to operate in an automated manner without depending on the operation of the driver or the like.

[0170] For example, the microcomputer 12051 can classify three-dimensional object data on three-dimensional objects into three-dimensional object data of a two-wheeled vehicle, a standard-sized vehicle, a large-sized vehicle, a pedestrian, a utility pole, and other three-dimensional objects on the basis of the distance information obtained from the imaging sections 12101 to 12104, extract the classified three-dimensional object data, and use the extracted three-dimensional object data for automatic avoidance of an obstacle. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 as obstacles that the driver of the vehicle 12100 can recognize visually and obstacles that are difficult for the driver of the vehicle 12100 to recognize visually. Then, the microcomputer 12051 determines a collision risk indicating a risk of collision with each obstacle. In a situation in which the collision risk is equal to or higher than a set value and there is thus a possibility of collision, the microcomputer 12051 outputs a warning to the driver via the audio speaker 12061 or the display section 12062 and performs forced deceleration or avoidance steering via the driving system control unit 12010. The microcomputer 12051 can thereby assist in driving to avoid collision.

[0171] At least one of the imaging sections 12101 to 12104 may be an infrared camera that detects infrared rays. The microcomputer 12051 can, for example, recognize a pedestrian by determining whether there is a pedestrian in images of the imaging sections 12101 to 12104. Such recognition of a pedestrian is, for example, performed by a procedure of extracting characteristic points in the images of the imaging sections 12101 to 12104 as infrared cameras and a procedure of determining whether it is the pedestrian by performing pattern matching processing on a series of characteristic points representing the contour of the object. When the microcomputer 12051 determines that there is a pedestrian in the images of the imaging sections 12101 to 12104, and thus recognizes the pedestrian, the sound / image output section 12052 controls the display section 12062 so that a square contour line for emphasis is displayed superimposed on the recognized pedestrian. The sound / image output section 12052 may also control the display section 12062 so that an icon or the like representing the pedestrian is displayed at a desired position.

[0172] One example of the vehicle control system to which the technology according to the present disclosure is applicable has been described above. The technology according to the present disclosure is appliable to the imaging section 12031 of the configurations described above. Specifically, the photodetector (for example, the photodetector 1) according to any of the embodiments described above and the modification examples thereof is applicable to the imaging section 12031. Applying the technology according to the present disclosure to the imaging section 12031 makes it possible to obtain a high definition shot image with less noise. This makes it possible to perform highly accurate control with the use of the shot image in the mobile body control system.

[0173] Although the description has been given with reference to the first and second embodiments, Modification Examples 1 to 7, the application examples, and the practical application examples, the present technology is not limited to the embodiments and the like described above and may be modified in a variety of ways. For example, Modification Examples 1 to 7 above have been described as modification examples of the first embodiment described above; however, the configuration of each of the modification examples may be combined with the second embodiment or any other modification example as appropriate.

[0174] It is to be noted that the effects described herein are merely exemplary and are not limitative and may include other effects.

[0175] It is to be noted that the present disclosure may also have the following configurations. (1) A photodetector, comprising: a semiconductor substrate; a plurality of microlenses; and a waveguide section provided between the semiconductor substrate and the plurality of microlenses, wherein the waveguide section includes a multilayered structure arranged in a vertical direction, wherein at least one layer of the multilayered structure is offset with respect to other layers of the multilayered structure in a horizontal direction and, wherein each layer of the multilayered structure includes: a color filter; and at least one separation section provided between portions of the color filter, wherein the at least one separation section includes an air gap provided therein. (2) The photodetector according to the above (1), wherein the at least one separation section further includes an insulating film surrounding the air gap. (3) The photodetector according to the above (1) wherein the at least one separation section further includes a light shielding portion. (4) The photodetector according to the above (3), wherein the at least one separation section further includes a light shielding portion provided below the air gap. (5) The photodetector according to the above (1), wherein the multilayered structure includes a first layer including a first color filter, a first separation section and a first air gap and a second layer including a second color filter, a second separation section and a second air gap and wherein the first air gap is connected to the second air gap through a top portion of the first layer and a bottom portion of the second layer. (6) The photodetector according to the above (5), wherein the first separation section includes a light shielding portion provided below the first air gap. (7) The photodetector according to the above (5), wherein a top portion of the first air gap is connected to a bottom portion of the second air gap. (8) The photodetector according to the above (1), wherein the multilayered structure includes a first layer and a second layer and wherein a coating layer is provided between the first layer and the second layer. (9) A photodetector, comprising: a semiconductor substrate; a plurality of microlenses; and a waveguide section provided between the semiconductor substrate and the plurality of microlenses, wherein the waveguide section includes a multilayered structure arranged in a vertical direction, wherein each layer of the multilayered structure is offset with respect to other layers of the multilayered structure in a horizontal direction and, wherein each layer of the multilayered structure includes: a color filter; and at least one separation section provided between portions of the color filter. (10) The photodetector according to the above (9), wherein the multilayered structure includes a first layer including a first color filter and a first separation section and a second layer including a second color filter and a second separation section and wherein the first separation section has a refractive index different than a refractive index of the second separation section. (11) The photodetector according to the above (10), wherein the first separation section and the second separation section are made of different materials. (12) The photodetector according to the above (10), wherein the first separation section and the second separation section are made of a same material. (13) The photodetector according to the above (10), wherein the first separation section has a refractive index greater than a refractive index of the second separation section. (14) The photodetector according to the above (10), wherein the second separation section has a refractive index greater than a refractive index of the first separation section. (15) The photodetector according to the above (9), wherein the multilayered structure includes a first layer including a first color filter and a first separation section, a second layer including a second color filter and a second separation section, and a third layer including a third color filter and a third separation section and wherein the first separation section, the second separation section and the third separation section each has a different refractive index. (16) The photodetector according to the above (15), wherein the first separation section, the second separation section, and the third separation section are each made of different materials. (17) The photodetector according to the above (9), wherein the multilayered structure includes a first layer including a first color filter and a first separation section, a second layer including a second color filter and a second separation section, and a third layer including a third color filter and a third separation section and wherein the first separation section, the second separation section and the third separation section each has a same refractive index. (18) The photodetector according to the above (9), wherein the multilayered structure includes a first layer including a first color filter and a first separation section, a second layer including a second color filter and a second separation section, and a third layer including a third color filter and a third separation section and wherein at least one of the first separation section, the second separation section or the third separation section includes a metal material. (19) The photodetector according to the above (18), wherein the metal material includes tungsten, titanium or titanium nitride. (20) The photodetector according to the above (9), wherein the multilayered structure includes a first layer including a first color filter and at least one first separation section, a second layer including a second color filter and at least one second separation section and a third layer including a third color filter and at least one third separation section and wherein at least one of the first layer, the second layer and the third layer includes one separation section provided on one end of the color filter and a remainder of the first layer, the second layer and the third layer includes two separation sections provided on each end of the color filter.

[0176] It should be understood by those skilled in the art that various modifications, combinations, sub-combinations, and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.

[0177] 1, 1A, 1B, 2A, 2B, 3A, 3B, 4, 5, 6A, 6B, 6C, 7, 8 photodetector 10 light-receiving section 11 semiconductor substrate 12 photoelectric conversion section 13 pixel separation section 20 light-condensing section 21 protection layer 22, 24, 27, 42 waveguide section 22A, 24A, 42A first layer 22B, 27B, 42B second layer 22C, 24C third layer 23 lens layer 23L microlens 30 multilayer wiring layer 31, 32, 33 wiring layer 34 interlayer insulating layer 44 light-blocking film 221, 223, 335 color filter 222, 224, 226 separation section 11S1 first surface 11S2 second surface S1 light incident side G air gap

Claims

1. A photodetector, comprising: a semiconductor substrate; a plurality of microlenses; and a waveguide section provided between the semiconductor substrate and the plurality of microlenses, wherein the waveguide section includes a multilayered structure arranged in a vertical direction, wherein at least one layer of the multilayered structure is offset with respect to other layers of the multilayered structure in a horizontal direction and, wherein each layer of the multilayered structure includes: a color filter; and at least one separation section provided between portions of the color filter, wherein the at least one separation section includes an air gap provided therein.

2. The photodetector according to claim 1, wherein the at least one separation section further includes an insulating film surrounding the air gap.

3. The photodetector according to claim 1, wherein the at least one separation section further includes a light shielding portion.

4. The photodetector according to claim 3, wherein the at least one separation section further includes a light shielding portion provided below the air gap.

5. The photodetector according to claim 1, wherein the multilayered structure includes a first layer including a first color filter, a first separation section and a first air gap and a second layer including a second color filter, a second separation section and a second air gap and wherein the first air gap is connected to the second air gap through a top portion of the first layer and a bottom portion of the second layer.

6. The photodetector according to claim 5, wherein the first separation section includes a light shielding portion provided below the first air gap.

7. The photodetector according to claim 5, wherein a top portion of the first air gap is connected to a bottom portion of the second air gap.

8. The photodetector according to claim 1, wherein the multilayered structure includes a first layer and a second layer and wherein a coating layer is provided between the first layer and the second layer.

9. A photodetector, comprising: a semiconductor substrate; a plurality of microlenses; and a waveguide section provided between the semiconductor substrate and the plurality of microlenses, wherein the waveguide section includes a multilayered structure arranged in a vertical direction, wherein each layer of the multilayered structure is offset with respect to other layers of the multilayered structure in a horizontal direction and, wherein each layer of the multilayered structure includes: a color filter; and at least one separation section provided between portions of the color filter.

10. The photodetector according to claim 9, wherein the multilayered structure includes a first layer including a first color filter and a first separation section and a second layer including a second color filter and a second separation section and wherein the first separation section has a refractive index different than a refractive index of the second separation section.

11. The photodetector according to claim 10, wherein the first separation section and the second separation section are made of different materials.

12. The photodetector according to claim 10, wherein the first separation section and the second separation section are made of a same material.

13. The photodetector according to claim 10, wherein the first separation section has a refractive index greater than a refractive index of the second separation section.

14. The photodetector according to claim 10, wherein the second separation section has a refractive index greater than a refractive index of the first separation section.

15. The photodetector according to claim 9, wherein the multilayered structure includes a first layer including a first color filter and a first separation section, a second layer including a second color filter and a second separation section, and a third layer including a third color filter and a third separation section and wherein the first separation section, the second separation section and the third separation section each has a different refractive index.

16. The photodetector according to claim 15, wherein the first separation section, the second separation section, and the third separation section are each made of different materials.

17. The photodetector according to claim 9, wherein the multilayered structure includes a first layer including a first color filter and a first separation section, a second layer including a second color filter and a second separation section, and a third layer including a third color filter and a third separation section and wherein the first separation section, the second separation section and the third separation section each has a same refractive index.

18. The photodetector according to claim 9, wherein the multilayered structure includes a first layer including a first color filter and a first separation section, a second layer including a second color filter and a second separation section, and a third layer including a third color filter and a third separation section and wherein at least one of the first separation section, the second separation section or the third separation section includes a metal material.

19. The photodetector according to claim 18, wherein the metal material includes tungsten, titanium or titanium nitride.

20. The photodetector according to claim 9, wherein the multilayered structure includes a first layer including a first color filter and at least one first separation section, a second layer including a second color filter and at least one second separation section and a third layer including a third color filter and at least one third separation section and wherein at least one of the first layer, the second layer and the third layer includes one separation section provided on one end of the color filter and a remainder of the first layer, the second layer and the third layer includes two separation sections provided on each end of the color filter.

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